Change the way the sortable changelists are rendered.
Move from using a table like the standard changelists, to using a list,
because getting jQueryUI, tbodys, empty drop-zones and receivers to all
work well consistently was an absolute nightmare (and/or impossibility).

Squashes commit hashes:
f5cb2b61a617dbab2519f996b7a98113e31500d2
c055d84da3ca9ca6b58f16fb371cd067b4ccd19c
0adacd4c1755c510c6a40314e84fcac302e412f7
f7d83e803ec999f3113f17e2ffad500a7eff58b5
0a4baff0f15f8cc64cf8ab0ba05965a5e7cca69a

Branch may still be at:
https://github.com/kezabelle/django-editregions/commits/sortables